3GPP (3rd Generation Partnership Project) TS (Technical Specification) release 8-based LTE (Long Term Evolution) is a leading next-generation mobile communication standard. Recently, LTA-A (LTE-advanced) which is based on 3GPP TS release 10 supportive of multi-carrier is being
3GPP LTE-A and its subsequent standards support a multi-carrier and this technology is referred to as carrier aggregation. One carrier corresponds to one cell, and resultantly, a terminal in a multi-carrier system may receive services from a plurality of serving cells.
In each serving cell, a sync signal and control channels for normal communication are generally transmitted. However, an introduction of a new type of cell is being considered in order to mitigate inter-cell interference and increase carrier extendibility.